Electrical protective device.



A. H. BAKKEN. ELECTRICAL PROTECTIVE DEVICE.

APPLICATION FILED MAR.24| 1914.

Patented; July 4, 1916.

WITNESSES UNITED STATES PATENT orrion.

ANDREW H. BAKKEN, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIG AND MANUFACTURING COMPANY, A CORPDRATION 0F IENNSYE- VANIA.

ELECTRICAL PROTECTIVE DEVICE.

Specification of Letters Patent.

Application filed March 24, 1914. Serial Ho. 826,231.

To all whom it may concern:

Be it known that I, ANDREW H. BAKKEN, a citizen of .the United States, and a resident of Vilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electrical Protective Devices, of which the following is a specification.

My invention relates to electrical protective devices, and particularly to mechanical retrieving devices for tripping coils of circuit interrupteis.

The object of my invention is to provide a device for resetting the movable core menr ber of the under-potential trip coil of a double throw circuit interrupter at such times, as the interrupter is closed.

Under-potential tripping coils are usu ally constructed to trip a circuit interrupter when the voltage of the circuit in which it is connected falls to half value. It is a well known fact that the movable core member of an electromagnet will not be delinergized sufficiently to move downwardly at half voltage when it requires only full volta e to sufiicientl ener ize the same to move D it upwardly through an appreciable air gap. I provide, in my invention, a device for .mechanically lifting the movable core mem her to set the same so that, when the potential drops to half its normal value, the core member will be sufficiently deenergized to move downwardly to trip the circuit interrupter.

Figure 1 of the accompanying drawings is a side elevational view of a double-throw circuit interrupter embodying myinvention, and Fig. 2 is a detail view of the operating dogs used in the circuit interrupter shown in Fig. 1.

A supporting panel 1 has attached to it, by a plurality of bolts, a frame work 2 for supporting a containing receptacle 3 and an operating mechanism 4. An operating lever 5 having a hollow inner end is pivotally mounted on pins (not shown) in the frame Work 2 and within the hollow portion thereof is disposed a second lever (5 also pivotally mounted on pins (notslpown) in the frame work 2.. A lever 8 IS pivotally mounted at a point intermediate its ends on a pm 7 and it has two spaced apart arms SRat one of its ends for reasons hereinafter set forth. A projection 9 is attached to one and of the lever S and a pin 10 is attached to each of Patented J nly 4, 1916.

the spaced apart arms 8. The leverarm 6' has pivotally attached to it at its inner end, two links 11 and 12 each' of which is provided with a slot in its outer end for receiving one of the pins 10 with which the arms 8 of the lever 8 are provided.

Two oppositely disposed dogs 13 and 14' are pivotally mounted on the pin 7 and are connected together by a spring 15. The dogs 13 and ll respectively have projections 16 and 17 for engaging a stationary pin 18 in the frame work 2 and projections 19 and 20 for engaging the projections 9 on the "lever arm 8. To the end of the lever 8 opposite the bifurcated end is attached a link 21 which is connected to a movable contactnrm (not shown) to operate a plurality of contact'members 22.

Since the construction of the operating mechanism of this type of circuit interrupter is explained in detail in application Serial No. 816,749, filed February 5, 1914; and, since the mere operating features of the interrupter are not parts of my inven tion, they will not be described in detail.

To the front side of the panel 1 is attached an overload tripping device 23 the movable core member 2-1 of which engages a bell crank lever which transmits its movement, through a link 26, a rocker arm 27 and a rod "28, loosely disposed within the lever arm (5, to a latch 29 that is pivotally mounted on the lever arm 5. The latch 29 is normally maintained in engagement with a notch in the end of the lever 8 by a spring 30, as shown, until such time as the rod 28 moves the latch 2) out of engagement there with. Two latches 3i and 32 are provided for latching the lever 5 in either of its two closed positions until manually released.

A cam member 33, that is attached to the inner end of the lever arm 6, is provided with two similarly formed faces 3% and Pivotally mounted on the frame work 2 is a lever 36 having a projection 37 substantially at right angles thereto and intermediate its ends which has a pin 38 for engagin-g the rocker arm 27. A second pro jection 39 of the lever 36 is operatively connected to the movable core member 40 of a low-voltage tripping device 41 which comprises, in addition to the movable core member 40, a stationary core member 42, a

coil 43 and a weight 44, all of which are suspended from the lower side of the frame work 2 substantially asshown.

A roller 45 is pivotally mounted in the upper end of the lever 36 for engaging either the face 34 or the face 35 of the cam member 33, according to the position of the lever arm 6.

Consider that the circuit interrupter is in the position shown in Fig. 1 and that the voltage on the line has dropped to a predetermined value, say 50% of its normal value, my invention operates as follows: The core member 40, being denergized suflieiently, moves downwardly until-it engages the projection 39 which also moves downwardly a relatively short distance to actuate the lever 36 and the projection 37 until the lever 36 assumes the position designated by the letter A in the dotted lines in Fig. 1. The pin 38 in the projection 37 rocks the rocker arm 27 which moves the rod 28 outwardly to trip the lever (5 free from the lever 5, as hereinbefore described. The lever 6 rises to a substantially horizontal position by reason of the contraction of the spring 15, which also quickly operates the dogs 13 and 14, in connection with the lever 8, to open the circuit interrupter.

Since the cam member 33 is attached to the lever arm (5, it moves downwardly when the lever arm- (5 moves to its horizontal position, and, since the roller 45 engages the cam face 34, the lever 36 is moved to the position designated by the letter B. The operation of the lever arm 36 moves the projection 39 and the movable core member 40 upwardly to reset the tripping device 41. The movable member 40 is retained in this position by the cam 33 until the voltage has assumed its normal value again or until the interrupter is again closed' Assuming that the lever 6, the dogs 13 and 14:, and the lever 8 are in the open or normal position, substantially as shown in F i 2 of the drawings, and that the voltage has resumed its normal value, then, ino -rder to close the circuit interrupter, the latch 31 is manually operated to release the lever arm 5 which is moved upwardly until the latch 99 engages the notch in the end of the lever 6 to operatively connect the two levers 5 and 6.. The cooperating lever members 5 and 6 may then be thrown'in either direc tion in accordance with the switch connections desired. For clearness of description, the assumption is made that the levers are moved downwardly. The cam 33 rotates upwardly to allow the roller 45 to follow the same until it reaches aposition limited by the rocker arm- 27 and the pin 38, as shown in Fig. 1. ,The movable member 40 is retained in its upper position by reason of the applied voltage being sufficiently high 'in value to energize the coil 43, as will be readily understood by those versed in the art.

Should the levers'5 and G be moved upwardl y from the normally open position, the face 35 of the cam member 33 will allow the roller 45 to follow it until the lever 36 assumes the position shown in Fig. 1. If the voltage drops sufficiently below its normal value, with the levers 5 and (l latched in their upper position by the latch 32, to del nergize the device 41, the movable member 40 will move downwardly to operate the lever arm 36, as hereinbefore described, and the rocker arm 27 will act through the rod 28 to disengage the lever arm (3 from the latch 29 and allow the lever (l to move downwardly to its horizontal position. As the cam 34 moves upwardly, the roller 45 is moved toward the position B by its engagement with the cum face 35 to thus reset the movable core member A), as hereinbcfore described.

An advantage of my invention is that a relatively smaller tripping cell may be used, with its accompanying saving in cost of construction.

\Vhile I have described my invention with reference. to a particular type of circuit interrupte and with respect to a particular constrlu-tion, I desire that only such limitations shall be imposed as come \vithinthe scope of the appended claims.

I claim as my invention:

1. .In a circuit interrupter, the combination with an operating lever arm, of a tripping device comprising a stationary core member, a movable core member, a coil for the same, a cam member operatively connected to the lever arm of the interrupter, a second pivotally mounted lever arm interposed between the said cam member and the said movable core member, and means operatively connected to the said second lever arm for tripping the said circuit interrupter.

2.-In a circuit interrupter, the combination with an operating lever arm, of a cam member operatively attached thereto, an electromagnet, a second lever arm interposed betwceuthe said cam and 'the movable core member of the said electromagnet, and means operatively connected to the said second lever arm for tripping the said circuit interrupter.

3. Ina circuit interrupter, the combination with an operating lever arm, of a cam member attached thereto, a tripping coil, means interposed between the cam member and the movable member of the tripping coil for resetting the same whenthe circuit interrupter is closed, and means operatively connected to said tripping coil for tripping the circuit interrupter.

4. In a circuit interrupter, the combination with an operating lever arm and a second lever arm operatively attached. thereto,

of an under-voltage tripping device comprising a cam member attached to the said second lever arm, an electromagnet, means operatively associated with the said cam trip coil, and a tripping mechanism operatively connected to the said bell crank lever arm.

6. In a circuit interrupter, the combination with an operating lever arm, and a second lever arm cooperating therewith, of a cam member attached to the second lever arm, an electromagnet, a bell crank lever arm relatively movable with the movable member of the said electromagnet and operatively connected thereto, and means operatively connected to the saidbell crank lever arm for tripping the second lever arm free from the first lever arm.

7. In a double-throw circuit interrupter, the combination with an operating lever arm and a second lever arm operatively connected thereto, of an overload tripping device, and a low-voltage tripping device comprising means operatively connected to the said second lever arm for resettingthe movable member thereof, and means for operating the said overload tripping device when the said low-voltage tripping device operates.

8. In a double-throw circuit interrupter, the combination with an operating arm and a tripping coil therefor, of means 'operatively connected to the movable core member of the tripping coil and adapted to be actuatedby the operating arm to reset the movable core member of the tripping coil when the circuit interrupter is tripped from either position.

9. In a double-throw circuit interrupter,

the combination with an operatingarm and a tripping coil therefor, of a cam member attached to the operating arm, and means interposed between the cam member and the movable member of the tripping coil for resetting the same when the circuit interrupter is tripped from either position.

In testimony whereof, I have hereunto subscribed my name this 28th day of Feb., 1914.

' ANDREW 1-1, BAKKEN.

Witnesses:

D. SAMUEL, B. B. HINES. 

